A group of scientists has identified the genes responsible for the dietary fibre content of flour and say healthier white bread could be available from supermarkets in just five years.

The research, led by Rothamsted Research and the John Innes Centre, found that the new white flour has as much as twice the fibre of traditional white flour and possesses all of the added health benefits that come from eating wholemeal bread, including reduced cancer, diabetes and obesity risks.

A slice of typical white bread has about 1g of fibre, whereas wholemeal has about 3g. A slice from a high-fibre white loaf could contain up to 2g.

Government advice suggests adults should eat about 30g of fibre a day, but the average adult in the UK  currently only eats about 18g.

Whilst wholemeal is widely regarded as being much healthier, white bread still outsells it, making up three quarters of the roughly 12 million loaves sold in the UK each day, according to the report.

Writing in the journal PLOS ONE, lead author Dr Alison Lovegrove of Rothamsted Research said the team had achieved the breakthrough by exploiting the results of an earlier genetic screen of over 150 different wheat varieties from around the world.

“We knew that the white flour made from one particular Chinese wheat variety, Yumai 34, was unusually high in fibre, but it’s not well suited for growing in the European climate.

“Using conventional breeding techniques, we crossed this high fibre trait into several other varieties. This allowed us to narrow down where in its genome the genes for high fibre are.

“We hope to go on and identify further genes that increase fibre content, thereby providing plant breeders, millers and food producers with even more options.”